diff --git a/test/unit/org/openstreetmap/josm/data/validation/tests/TagCheckerTest.java b/test/unit/org/openstreetmap/josm/data/validation/tests/TagCheckerTest.java
index f0727426def..c8f45ab6473 100644
--- a/test/unit/org/openstreetmap/josm/data/validation/tests/TagCheckerTest.java
+++ b/test/unit/org/openstreetmap/josm/data/validation/tests/TagCheckerTest.java
@@ -19,11 +19,13 @@
 import org.openstreetmap.josm.data.osm.Tag;
 import org.openstreetmap.josm.data.validation.Severity;
 import org.openstreetmap.josm.data.validation.TestError;
+import org.openstreetmap.josm.testutils.annotations.I18n;
 import org.openstreetmap.josm.testutils.annotations.TaggingPresets;
 
 /**
  * JUnit Test of {@link TagChecker}.
  */
+@I18n
 @TaggingPresets
 class TagCheckerTest {
     List<TestError> test(OsmPrimitive primitive) throws IOException {
diff --git a/test/unit/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayerTest.java b/test/unit/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayerTest.java
index 4f085766ad3..0852b7a0618 100644
--- a/test/unit/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayerTest.java
+++ b/test/unit/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayerTest.java
@@ -23,6 +23,7 @@
 import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.spi.preferences.Config;
 import org.openstreetmap.josm.testutils.annotations.BasicPreferences;
+import org.openstreetmap.josm.testutils.annotations.I18n;
 import org.openstreetmap.josm.testutils.annotations.Main;
 import org.openstreetmap.josm.testutils.annotations.Projection;
 
@@ -32,6 +33,7 @@
 @BasicPreferences
 @Main
 @Projection
+@I18n
 class MarkerLayerTest {
     /**
      * Setup tests
diff --git a/test/unit/org/openstreetmap/josm/gui/tagging/presets/PresetClassificationsTest.java b/test/unit/org/openstreetmap/josm/gui/tagging/presets/PresetClassificationsTest.java
index 910c568eb2a..fc0125dabb6 100644
--- a/test/unit/org/openstreetmap/josm/gui/tagging/presets/PresetClassificationsTest.java
+++ b/test/unit/org/openstreetmap/josm/gui/tagging/presets/PresetClassificationsTest.java
@@ -19,11 +19,13 @@
 import org.openstreetmap.josm.data.osm.Way;
 import org.openstreetmap.josm.gui.tagging.presets.TaggingPresetSelector.PresetClassification;
 import org.openstreetmap.josm.gui.tagging.presets.TaggingPresetSelector.PresetClassifications;
+import org.openstreetmap.josm.testutils.annotations.Territories;
 import org.xml.sax.SAXException;
 
 /**
  * Unit tests of {@link PresetClassifications} class.
  */
+@Territories
 class PresetClassificationsTest {
 
     static final PresetClassifications classifications = new PresetClassifications();
diff --git a/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetReaderTest.java b/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetReaderTest.java
index fa414d81c82..391e282bb5d 100644
--- a/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetReaderTest.java
+++ b/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetReaderTest.java
@@ -17,6 +17,7 @@
 import org.openstreetmap.josm.TestUtils;
 import org.openstreetmap.josm.gui.tagging.presets.items.Check;
 import org.openstreetmap.josm.gui.tagging.presets.items.Key;
+import org.openstreetmap.josm.testutils.annotations.Territories;
 import org.xml.sax.SAXException;
 
 /**
@@ -76,6 +77,7 @@ void testExternalEntityResolving() throws IOException {
      * @throws SAXException if any XML error occurs
      * @throws IOException if any I/O error occurs
      */
+    @Territories
     @Test
     void testReadDefaultPresets() throws SAXException, IOException {
         String presetfile = "resource://data/defaultpresets.xml";
diff --git a/test/unit/org/openstreetmap/josm/testutils/annotations/I18n.java b/test/unit/org/openstreetmap/josm/testutils/annotations/I18n.java
index 4baedecb66e..ae515470e51 100644
--- a/test/unit/org/openstreetmap/josm/testutils/annotations/I18n.java
+++ b/test/unit/org/openstreetmap/josm/testutils/annotations/I18n.java
@@ -45,15 +45,22 @@ public void beforeEach(ExtensionContext context) {
             String language = AnnotationUtils.findFirstParentAnnotation(context, I18n.class).map(I18n::value).orElse("en");
             if (!Locale.getDefault().equals(LanguageInfo.getLocale(language, false))) {
                 org.openstreetmap.josm.tools.I18n.set(language);
+                // We want to have a consistent "country", so we don't use a locale with a country code from the original locale.
+                // Unless someone specified it via the <lang>_<country> syntax.
+                if (!language.contains("_")) {
+                    Locale.setDefault(LanguageInfo.getLocale(language, false));
+                }
             }
         }
 
         @Override
         public void afterEach(ExtensionContext context) {
-            if (!Locale.ENGLISH.equals(Locale.getDefault())) {
+            Locale original = org.openstreetmap.josm.tools.I18n.getOriginalLocale();
+            if (original == null) {
                 org.openstreetmap.josm.tools.I18n.set("en");
-                org.openstreetmap.josm.tools.I18n.set(org.openstreetmap.josm.tools.I18n.getOriginalLocale().getLanguage());
-                Locale.setDefault(Locale.ENGLISH);
+            } else if (!original.equals(Locale.getDefault())) {
+                org.openstreetmap.josm.tools.I18n.set(original.getLanguage());
+                Locale.setDefault(original);
             }
         }
     }
diff --git a/test/unit/org/openstreetmap/josm/testutils/annotations/TaggingPresets.java b/test/unit/org/openstreetmap/josm/testutils/annotations/TaggingPresets.java
index 9901693971a..42d970a0547 100644
--- a/test/unit/org/openstreetmap/josm/testutils/annotations/TaggingPresets.java
+++ b/test/unit/org/openstreetmap/josm/testutils/annotations/TaggingPresets.java
@@ -7,6 +7,8 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 import java.util.Collection;
+import java.util.Locale;
+import java.util.Objects;
 
 import org.junit.jupiter.api.extension.BeforeAllCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
@@ -31,6 +33,7 @@
 
     class TaggingPresetsExtension implements BeforeEachCallback, BeforeAllCallback {
         private static int expectedHashcode = 0;
+        private static Locale lastLocale;
 
         @Override
         public void beforeAll(ExtensionContext extensionContext) throws Exception {
@@ -47,9 +50,10 @@ public void beforeEach(ExtensionContext extensionContext) {
          */
         public static synchronized void setup() {
             final Collection<TaggingPreset> oldPresets = org.openstreetmap.josm.gui.tagging.presets.TaggingPresets.getTaggingPresets();
-            if (oldPresets.isEmpty() || expectedHashcode != oldPresets.hashCode()) {
+            if (oldPresets.isEmpty() || expectedHashcode != oldPresets.hashCode() || !Objects.equals(lastLocale, Locale.getDefault())) {
                 org.openstreetmap.josm.gui.tagging.presets.TaggingPresets.readFromPreferences();
                 expectedHashcode = org.openstreetmap.josm.gui.tagging.presets.TaggingPresets.getTaggingPresets().hashCode();
+                lastLocale = Locale.getDefault();
             }
         }
     }